Add option to insert images properly

[bviktor]

Currently this plugin doesn't change the way media is added, i.e. it's inserted into posts as <img src....

But Markdown syntax should be:

![](foobar.png)

Also, the way wordpress adds images is stupid, coz it includes the full URL, which will break if you ever change your domain name, and then you have to replace ALL image links in ALL posts. Instead, it should be like:

![](/wp-content/uploads/2018/08/Clipboard01-6.png)

This way the images will load properly, regardless of domain name and protocol (HTTP / HTTPS)

Please add this.